Photoresponsive apparatus



March 7, 1939.

C. CHILOWSKY I PHOTORESPONSIVE APPARATUS 2 Sheets-Sheet I Filed March 10, 1937 lNVENTOR M .ATTO RN E-YS March 7, 1939'. c KY 2,150,052

PHO TORESPONS IVE APPARATUS Filed March 10, 1937 2 Sheets-Sheet 2 INVENTOR M M BY ATTQRNEYS Patented Maro 7, 1939 UNITED STATES PATENT OFFICE Application March 10, 1937," Serial No. 130,103 In France March 14, 1936 20 Claims.

In a, copending application, Serial No. 40,657, of which this case is a continuation in part, I described methods and apparatus for translating modifications of illumination into mechanical actions by making use of a photo-chemical reaction of gases obtained through the electrolysis of a liquid, accompanied by volume variations; this method is chiefly characterized by the fact that the elements necessary for the reaction are placed in a closed chamber and act through an elastic membrane upon a mercury column intended to open and close electric contacts.

I'he object of the present invention is to provide apparatus of the type above referred to which are of a much smaller size, simple of construction, strong, and capable of working in a substantially quicker manner than apparatus of the same type described in my prior application.

An important feature of the present invention lies in the fact that the reaction chamber is constituted by a flat chamber lying parallel to a glass membrane of any suitable type, said chamber forming, from a structural point of view, a whole with the membrane.

The apparatus therefore merely includes a number of plates forming a whole and a U- shaped tube filled with mercury, branched in a suitable manner to an aperture provided in one of these plates, and which may be included in said whole; this tube may, in fact, consist of the assembly of two plates forming a whole with the other plates.

Other features of the present invention will result from the following detailed description of some specific embodiments thereof.

Preferred embodiments of the present invention will be hereinafter described, with reference to the accompanying drawings, given merely by way of example, and in which:

Fig. 1 is a sectional view of a portion of an apparatus according to the present invention, including the reaction chamber, the membrane and the tube elements connecting this portion of the apparatus with the U-shaped tube containing mercury on the one hand and the electric circuit on the other hand;

Fig, 2 is a plan view of the same portion of the apparatus;

Fig. 3 is a sectional view of a modification relative to an apparatus of the same kind;

Fig. 4 is a plan view of the main portion of the same app r Figs. 5 and 6 are sectional views of two other embodiments of the main portions of apparatus according to the invention, respectively;

(o1. zoo-52) Fig. 7 is a, plan view showing the construction of a U-shaped tube adapted to receive mercury, said tube being formed in the wall of a plate adapted to be assembled with the other plates of the apparatus;

Fig. 8 is a cross section of the plate of Fig. 7;

Fig. 9 is a sectional view of another embodiment of the main portion of an apparatus according to the present invention;

Fig. 10 is a similar view corresponding to a modification;

Fig. 11 is a front view illustrating a modification of the portion of the apparatus in which mercury is movable;

Fig. 12 is a view, similar to Fig. l1, showing an arrangement for acting mechanically upon mercury; 1

Fig. 13 is a sectional view on the broken line X-X of Fig. 12;

Fig. 14 is a plan view of a portion of an apparatus according to the present invention in which the gas pressure acts directly upon the mercury present in the apparatus;

Fig. 15 is a sectional view of the apparatus of Fig. 14;

Figs. 16 and 17 are a sectional view, and a plan view, respectively, of an apparatus essentially constituted by two plates and amembrane and in which the different elements are formed in said plates;

Figs. 18 and 19 are a sectional view and a plan view, respectively, of an embodiment of the reaction chamber of an apparatus of the type illustrated by the other figures;

Figs. 20 and 21 are similar views corresponding to another embodiment of the electrodes and the reaction chamber;

Referring first to Fig. 1 and Fig. 2, I have shown at l and 2 two relatively thick glass discs, between which is placed a thin disc 3, constituting the elastic membrane. Such a construction is described in my prior application above referred to. Discs I and 2 are slightly curved on their inner walls in such manner as to permit glass membrane 3 to move with a slight amplitude under the effect of pressure variations.

According to the present invention, a glass plate or disc 4, of suitable cross section, for instance as shown by Fig. 1, is welded, or glued in the hot state, to glass disc I, so as to form a chamber, or chambers, between glass disc I and the portion, or portions, of plate 4, that is, or are, not applied against said disc I. The whole of discs l and 4 and 2 and 3, suitably juxtaposed as above explained, is welded along the periphery, conveniently in a single operation.

The reaction chamber is formed by the space 8 present between discs I and 4. The two electrodes which produce electrolysis inside said chamber may, for instance, be constituted by two tubes of platinum-iridium 6 and I, inserted from the periphery 'for instance by passing through suitable notches provided in plates i and/or 4, and welded in a fluidtight manner at the periphery, these tubes being capable of use also for filling the chamber 8 with liquids and gases.

It,will be readily understood that the liquid present in chamber 8 will be located, under the effect of the capillary forces acting thereon, in the peripheral annular portion 8", whereas the gases produced by the electrolysis will be caused, also under the action of the capillary forces, to occupy the central portion, of greater height, thus forming a kind of gas bubble 8. This bubble is fully immersed in the surrounding liquid, like the bubble of a spirit level.

With such an arrangement, the contact between the liquid and the gas is given the maximum possible area, the liquid occupying the annular portion which surrounds the bubble being readily set in circulation under'the action of the gaseous bubbles disengaged from electrodes 6 and l. I thus obtain an apparatus in which, owing to the small distance between the walls, the interchanges between the gases and the liquid, and consequently the absorption of the gases obtained under the'action of light from the liquid, are brought to their maximum value, whereby the working of'the apparatus is considerably accelerated.

Furthermore, I avoid any danger of explosion under the effect of a sudden action of light, as can easily be understood from the general considerations'set forth in the prior application above mentioned. Plate 1 is providedwith an orifice 9 placing the inside of chamber 8 in communication with the chamber formed between plate I and flexible membrane 3.

However, in order to still further increase mechanical safety against explosion, I may limit the area of the portion of plate I which corresponds to the reaction chamber. Such an arrangement is illustrated by Fig. 1a, which shows an embodiment in which most of the areas of discs i and 4 are welded together, along the periphery, only the central portion, forming the reaction chamber in question.

In order to further increase safety, this chamber 8 and the chamber adjacent to the membrane are connected only through a very narrow passage 5 opening into aperture 9, in such manner as to brake the transmission of sudden temporary overpressures through this passage filled with liquid and of very small cross section. the chamber between membrane 3 and plate'2 is generally filled with an inert gas, such for instance as hydrogen, and it is connected with the tube in which the. mercury column is moving (and which is not shown in Figs. 1 and 2). This communication can be established (as explained in the prior application above mentioned) either through a tube such as In, for instance of glass or-a metal such as platinum, welded to the periphery, or through a tube, such as II, welded to the central portion of the glass plate 2, which is provided with a hole for this purpose.

It will'be readily understood that an apparatus such as above described is of very small size and of an extremely simple and strong construction.

It should be well understood that it may be sufficient to weld together discs or plates I, 3 and 4, disc 2 being, if desired, glued in the periphery of membrane 3 through a suitable fiuidtight cement.

In Fig. 3, I have shown, in section, an apparatus of the same type, completed by a U-shaped tube filled with mercury and carrying electric contacts. In this figure the glass plate 4 is so shaped, in section, as to form an annular chamber l2 in which electrolysis takes place. I have shown at l3 the portion of this chamber occupied by the gases. I4 is the tube containing the mercury column.

Fig. 4 shows, in plan view, the left hand side of the apparatus of Fig. 3. It will be readily understood that, with such an arrangement, the liquid circulation is further improved, as also the exchanges between'this liquid and the gases.

It is possible, by further reducing the size of the chambers such as 8 and I2 (by placing the walls closer to each other), to obtain the formation, between said walls, during the electrolytic action, of a kind of emulsion of gas and liquid which fills the whole of the chamber, which further facilitates, under the action of light, the absorption of the gases formed by electrolysis.

I may also, according to the present invention, employ, instead of the flat thin glass membrane 3, membranes of corrugated glass, so as to avoid possible differences of expansion between the thin membrane and the thick glass plates, which might in some cases have a detrimental action. Furthermore, this arrangement improves the sensitiveness of the apparatus.

Instead of making use of apparatus including four discs, as above described with reference to Figs. 1 to 4, I may also, according to the present invention, make use of apparatus consisting of three discs, as shown for instance by Fig. 5, provided that the reaction chamber formed in a glass plate 4 has a sufflciently narrow profile and a sufficiently small width for avoiding the danger of breaking of membrane 3 in the portions thereof where it is practically free, under the effect of a possible strong suction in parts l2.

In order to avoid any detrimental differences of coefficients of temperature, it is possible, ac-- cording to the present invention, to constitute the active portion of the apparatus not of thick glass plates, with the interposition of thin plates, but wholly of thin plates from the same cast, welded together along the periphery. Such an arrangement is shown by Fig. 6.

This embodiment is of the same type as that of Fig. 1, but it includes three thin plates 4', 3'

and 2, supported by reinforcements l5 and I8, and associated with a membrane as previously described.

In all the apparatus above described, I may, according to the present invention, silver-plate or give a reflecting appearance, to the part of the apparatus opposed to the reaction chamber, in such manner as to increase the luminous effect.

In the devices above described, the reaction chamber and the three glass plates are connected together, in such manner as to form a single block, by juxtaposition and peripheral welding. This arrangement has considerable advantages from the point of view of strength, simplified construction, and simplification for establishing the communications between the various chambers, owing to the possibility of employing mere perforations instead of tubes. However, in all these embodiments, the tube in which the mercury column is movable and which carries the electric contacts remains a separate element from a constructional point of view.

An additional desirable feature of the present invention, applicable as well to apparatus of the type just above set forth as to all apparatus based upon the same principle, is that the construction of the structure intended to contain the mercury column may be simplified by forming the necessary space in plates. In the case of apparatus forming a single block as above mentioned, the construction can be still further simplifled by constituting the apparatus by a juxtaposition of plates.

According to the present invention, the conduit adapted to contain the mercury column and the electric contacts is constituted by two juxtaposed glass plates, welded together over their whole areas. Before welding these two plates together, I form in one of these plates, or in both of them, a recess in the shape of a channel, in which the mercury column is intended to move, and of a chamber intended to contain the gases located above one of the branches of the column. I may also, according to the invention, provide recesses for the passage of the electric contacts. The two plates or discs, when welded together, thus form the desired fluid tight conduit. The recesses may be obtained in various manners. I may for instance form the channels by mechanically machining the glass plate through grinding tools, or the like, I may also obtain this channel by a deformation of glass, for instance by printing in the hot state under pressure, by moulding, and so on. The channels may be formed between two thick glass plates, or between a thick glass plate and a thin glass plate, or again between two thin glass plates.

The flat element containing the channel for the mercury column may, according to the present invention, be juxtaposed to the other plates forming the remainder of the apparatus, by being welded on the periphery with the other plates or membranes, and this preferably in a single welding operation along the periphery of the whole. It is thus possible to make complete photo-relays consisting of a single block including the reaction chamber, the flexible membrane, the mercury column and the contacts. The communication between the channel containing the mercury column and the chamber filled with inert gas located between the flexible membrane and the plate in.

which is formed the channel can be obtained through a single hole in the glass plate.

In Fig. 7, I have shown; in front view, a glass disc in the surface of which there is formed a groove 2| containing the mercury column. This groove may be of any suitable shape, and in particular the shape of a U. At the top of the left branch of the U, the plate is provided with a hole 22 which places the inside of the groove in communication with the remainder of the apparatus. The right hand branch communicates with a chamber 23 also formed in the glass plate 20 and intended to reduce the pressure variations formed by the displacements of the mercury column. I have shown at 24 and 25 two plugs of a porous material (which may, if desired, be replaced by portions of reduced section of the channel), intendedto prevent the mercury from penetrating into 22 and 23. I have shown at 21, 26, 28 and 29, contacts embedded in the glass wall and intended to ensure electric communications with the mercury column. Disc 23 is welded over the whole of its area with a second disc 33 (Fig. 8) in such manner as to form the chamber in which the mercury column moves. Wires 26, 21, 28 and 23 are welded between the two plates. The introduction of mercury can take place through one or several passages provided, for instance, for the contacts and which may be subsequently welded. I may also fill the apparatus through a tube 3! the end of which is subsequently closed in a fluidtight manner. It should be well understood that disc 30 can be made of smaller size than disc 2E and may merely con- ,sists of a thin plate covering only the hollow or recessed portions of plate 20.

In Fig. 9, I have shown a complete apparatus of the type of that of Fig. 1, in which plate 2 is replaced by an assembly of plates 2!] and 30, the whole being welded together at the periphery.

Fig. 10 shows an embodiment of the portion of the apparatus containing the mercury column, according to which said portion of the apparatus consists of a thick plate 36 to which there is welded a thin plate 20 in which the channel for the mass of mercury is formed by compression.

In the embodiment of Fig. 11, the disc is provided with the same chambers and recesses as in Fig. 7, but it is arranged circularly near the periphery. A short mercury column 32 moving along a graduated scale acts as an indictor of the light intensity, the apparatus thus forming a photometer.

I may also provide a whole series of contacts n n etc., permitting, according to the position of column 32 (which, as a matter of fact, may be of any length whatever) to act upon various electricalresistances and thus to transmit to a distance the indications of the apparatus, or to operate a series of telemechanical controls.

In the devices above described, the displacement of the flexible membrane is transmitted to the mercury mass through an inert gas. However, according to the present invention, I act also directly through the flexible membrane upon the mass of mercury present between the flexible membrane and a fixed thiclr plate in which is formed a recess filled with mercury. Such an embodiment is shown by Figs. 14 and 15, in which a plate 33 is provided with a recess filled with mercury and having the shape of a circular space 34 and a channel 35 which may open, if so desired, into a chamber 55 filled with gas, said chamber being also possibly formed in the mass of plate 33. In this conduit 35 are provided the desired contacts. The flexible blade 3 is in direct contact with the surface of the mercury filling chamber 34. Owing to the resistance of the capillary forces of mercury, the latter wholly fills chamber 34 and has no tendency to penetrate between plates 3 and 33. The slight displacements of membrane 3 exert a pressure upon the mercury by more or less compressing it. This causes said mercury to ascend more orless in tube 35 in such manner as to act upon contacts 56 and 51. It is perfectly clear that it is possible,

by disposing two plates similar to 33 on either side of the flexible membrane, to obtain that, with the displacement of this membrane, mercury moves upwardly in one compartment and downwardly in the other one. It sufiiccs to place time of these compartments in communication with an apparatus having a membrane for obtaining the desired openings and closing of the contacts.

My invention further includes another embodi- 7 ment arranged in such manner that, in the case of mercury columns or relatively large section, or even of normal section, it is possible to act bn said columns in the event of the latter being broken under the eflect 01 a shock, or for avoiding the breaking or these columns for instance during transportation. For this purpose, according to the present invention, I adjoin to the mercury column, in communication therewith, at a suitable point, means (such for instance as a little elastic bellows, a small manometric shell, a flexible blade, etc.) for displacing or forcing back this mercury column, these means serving either to immobilize the column during transportation by bringing it into contact with plugs or to reform it in case of breaking, or finally, in a general manner, to suitably adjust its height.

Such an arrangement is shown by Figs. 12 and 13. The portion of the apparatus that is considered is formed, in this case, by two plates 20 and 80 between which there is formed a recess adapted to contain the mercury column. This recess includes a portion 31 in which is present a mass oi! mercury. One of the plates, 20 or 30, may be thin, or it may be provided with movable or deformable means, in such manner that by merely depressing it in the direction of the arrow A of Fig. 13, mercury from 31 can be caused to move upwardly to plugs 24 and 25, so that the mercury column is brought back into a unitary state.

It is also possible, by making use of suitable means, such as a screw or the like, to exert a constant pressure upon this plate 20 during transportation of the apparatus, in such manner as to maintain, during this time, the mercury column, applied against the plugs, thus avoiding any risk of breaking.

I may also provide the possibility of acting by' external pressure upon chamber 23 in the direction oi the arrow A so as to bring back the mercury toward the rear. This action can be exerted either merely with one finger or through any mechanical device, including a screw or other means.

I may also, according to the present invention, provide apparatus which, instead of being formed by the juxtaposition oi several. glass plates or discs consist oi the juxtaposition of two plates between whichthere is placed a membrane and in which are formed. all the elements of the apparatus, disposed in the same plane. Such an embodiment is shown by Figs. 17- and 16.

In these figures, I have shown, at 46 and 11,

two glass plates disposed side by side, and in each of which there is formed one half of the parts 42 and ll of the reaction chamber. The membrane i is disposed between the two plates, the space located between plate 48 and the membrane communicating with the reaction chamber 44 through passage 48 and the space between the membrane and plate 41 communicating through a passage with a U-shaped channel 50 formed in plate 41 and receiving the movable mercury column and also contacts a, b, c. An apparatus oi'this type, constituted by two recessed plates welded together and by a membrane interposed between these two plates constitutes a great simplification of construction permitting the manufacture of reliable apparatus of very small size.

In order to increase the rapidity of absorption the reaction chamber, I have devised an embodiment intended to produce the formation of the gases over a portion as wide as possible of the reaction chamber. This embodiment is shown by Figs. 18 and 19, in which the electrodes 6' and 1 are wound in spiral shape, with close spires and are placed on the bottom of the reaction chamber formed between plates 4 and I in such manner as to disengage gases over the whole or the periphery of the gaseous bubble.

It is clear that the number of spires and their precise arrangement can vary. For instance, in the embodiment of Figs. 20 and 21, I have shown two electrodes made in the form of a great number of spires disposed on the bottom of the reaction chamber or even embedded in the upper sur face of plate I. In this embodiment, I have also shown another constructional feature of the pro..-

ent invention, intended, by forming several small gaseous bubbles, to further increase the surface of contact between the liquid and the gases. This arrangement consists in forming on the under face of plate 40, which forms the upper wall of the reaction chamber, a great number of points or projections ll, extending in a downward direction and distributed over the whole area of the plate. The shape of these projections and their disposition and distribution may vary. For instance, they may constitute a whole analogous to a grid. In this way, the thickness of the gaseous layer thus divided can be very much reduced, said layer being maintained in very intimate contact with the liquid.

In a general manner, while I have, in the above description, disclosed what'I deem to be practical and efficient embodiments of the present invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended within the scope of the appended claims.

What I claim is:

. 1. An apparatus which comprises, in combination, a cup-shaped plate, and a thin glass membrane fixed in a fluid-tight manner at its periphery to said plate so as to form therewith a reaction chamber adapted to contain chemical substancescapable of producing pressure variations in said chamber in response to variations of the illumination thereof, and at least one rigid plate associated with said membrane for limiting the gisplacements thereof and forming a support for 2. An apparatus of the type described which comprises, in combination, two thick glass plates assembled together along their peripheries and having their inner walls so shaped as to leave between them a lens-shaped space, a thin glass membrane between said plates having its edge held in a fluidtight manner between the peripheral portions of said plates, one of said plates being provided with a hole extending through it, and a rigid glass plate having a concavity therein fixed along its periphery in a'fluidtight manner to the periphery of the last mentioned plate, in such manner as to form between these two last mentioned plates a reaction chamber, adapted to contain chemical substances capable of producing pressure variations in said chamber in response to variations of the illumination thereof, said chamber communicating with one face of said membrane through said hole.

3. An apparatus according to claim 2 in which said rigid cup-shaped plate is so shaped that said reaction chamber is of lens-shaped section.

4. An apparatus according to claim 2 in which said hole is provided in a part of the corresponding plate against which the peripheral part of the cup-shaped rigid plate is fixed, a very narrow passage being provided between these two last mentioned plates so as to connect said reaction chamber with said hole.

5. An apparatus according to claim 2 in which the concavity of said rigid plate is of annular shape so as to form an annular space between the two last mentioned plates of claim 2.

6. An apparatus of the type described which comprises, in combination, a shallow cup-shaped plate, a thin glass membrane fixed in a fiuidtight manner to the periphery of said plate so as to form therewith a reaction chamber adapted to contain chemical substances capable of producing pressure variations in said chamber in response to variations of the illumination thereof, and a rigid glass plate fixed to the first mentioned plate along the periphery thereof, on the other side of said membrane, the inner wall of said last mentioned plate being shaped so as to limit the displacement of said membrane and I to form a support for it.

'7. An apparatus of the type described which comprises, in combination, at least three thin glass plates welded together along their periphery, the intermediate plate forming a glass membrane and the space between said membrane and another of said three plates forming a reaction chamber adapted to contain chemical substances capable of producing pressure variations in said chamber in response to variations of the illumination, and a rigid casing surrounding said three plates so as to protect them and to limit the deformations thereof.

8. An apparatus according to claim '7, in which said casing consists of two rigid plates welded together along their peripheries and respectively disposed on either side of said group of three thin glass plates.

9. An apparatus which comprises, in combination, a structure forming a reaction chamber containing chemical substances capable of producing variations of the pressure in said chamber in response to variations of the illumination thereof, at least one thin glass wall forming a membrane closing said chamber, and two glass plates assembled together in a fiuidtight manner, at least one of said plates being provided with a recess forming a channel communicating with the outer face of said membrane, and a column of mercury in said channel.

10. An apparatus which comprises, in combination, a shallow cup-shaped plate, a thin glass membrane fixed in a fiuidtight manner to the periphery of said plate so as to form therewith a reaction chamber adapted to contain chemical substances capable of producing pressure variations in said chamber in response to variations of the illumination thereof, at least one rigid glass plate fixed to the periphery of said first mentioned elements, for limiting the displacements of said membrane and forming a support for it, and two glass plates assembled together in a fiuidtight manner at least one of said plates being provided with a recess forming a channel between these two last mentioned plates and communicating with the outer face of said membrane, and a column of mercury movable in said channel.

11. An apparatus according to claim 9. in

,being short, so as to occupy,

which said channel is of circular shape and located near the periphery of said two plates, the column of mercury movable in said channel along said channel, a position depending upon the illumination of said chamber.

12. An apparatus according to claim 9 in which said channel is of circular shape and located near the periphery of said two plates, the column of mercury movable in said channel being short, so as to occupy, along said channel, a position corresponding to the illumination of saidchamber, and a plurality of contacts extending into said channel at different points thereof, so as to cooperate with said column of mercury.

13. An apparatus of the type described which comprises, in combination, two rigid glass plates fixed to each other along their peripheries so as to leave a space between them, a thin glass membrane having its edge caught between the peripheries of said plates, one of said plates being of curved shape on its inner side so as to limit the deformations of said membrane and to form a support for it, said last mentioned plate being provided with a hole extending through it, a shallow cup-shaped plate fixed at its periphery to said last mentioned plate, so as to form between these two last mentioned plates a reaction chamber adapted to contain chemical substances capable of producing pressure variations in said chamber in response to variations of the illumination thereof, the other of the two first mentioned rigid glass plates being provided with a recess on its inner side, facing said membrane, so as to form with said membrane a closed chamber and a conduit at the top of said last mentioned chamber, mercury in said last mentioned chamber, and electric contacts in said conduit adapted to cooperate with said mercury.

14. An apparatus of the type described which comprises, in combination, two rigid glass plates fixed to each other in a fluidtight manner along their peripheries, said glass plates being provided,

in their inner faces applied against each other, with recesses so as to form a reaction chamber adapted to contain chemical substances capable of producing pressure variations in said chamber in response to variations of the illumination thereof, a shallow space, substantially lens-shaped, communicating with said chamber, and a channel communicating with said space, and a thin glass membrane forming a diagonal partition in said space, so that the part of said space located on one side of said membrane is in communication with said chamber and the other part of said space located on the opposite side of said membrane is in communication with said channel, said channel being partly filled with mercury.

15. An apparatus according to claim 1 further including two electrodes consisting of thin wires extending over a large portion of the area of said reaction chamber.

16. An apparatus according to claim 1 further including two electrodes consisting of two wires wound circularly over anannular portion of the area of said reaction chamber.

17. An apparatus according to claim 1 in which said cup-shaped plate is provided, on its inner face, with a plurality of projections, distributed over its inner wall, so as to facilitate the production of a plurality of gaseous bubbles.

18. An apparatus'according to claim 7 in which said thin glass plates are transparent and at least one plate of said casing is annular whereby the central parts of said thin glass plates are directly visible from the outside.

19. An apparatus which comprises, in combination, a structure forming a reaction chamber containing chemical substances capable 0! producing variations of the pressure in said chamber in response to variations of the illumination thereof, at least one thin glass wall forming a membrane closing said chamber, means for protecting said membrane and limiting the deformations theroei, means forming a conduit communicating with the outer face or said membrane, a mass of mercury in said conduit, and movable means in connection with said conduit for exerting a wall can be transmitted through said mass 01' mercury to the mercury in said conduit.

CONSTANIIN CHILOWSKY. 

